1. Field of the Invention
This invention relates to a novel lubricant additive which utilizes a nonionic fluorochemical polymer surfactant as an important ingredient thereof, a modified lubricant composition using the additive hereof, and a method of using the additive hereof.
2. Background of the Prior Art
The prior art discloses various engine lubricant additive compositions containing polytetrafluoroethylene (PTFE) particles and a nonionic, anionic or cationic fluorochemical surfactant for stabilizing the dispersion of the particles in the lubricant. The PTFE particles perform the function of lubrication, being carried to the metal surface of the engine and adhering to it. An example of such a lubricant additive is found in U.S. Pat. No. 4,244,173 which teaches a lubricant additive containing PTFE particles and a nonionic fluorochemical surfactant sold under the trade name ZONYL.RTM., a modified polyethylene glycol-type surfactant.
Other patents disclose lubricant additives of varying compositions. U.S. Pat. Nos. 4,159,252 and 4,127,491 each disclose lubricants including a halogenated organic lubricant or halocarbon oil, among other ingredients. U.S. Pat. Nos. 2,582,282 and 2,603,627 disclose other halogenated polymers or condensation products useful as lubricants or oil additives. U.S. Pat. No. 2,510,540 notes that polymers of propylene oxide have been suggested as lubricants some time ago, but were deemed unsatisfactory because of their low viscosity. The patent discloses a mineral oil additive comprising a mixture of homopolymeric ethers of 1,2-epoxy linear hydrocarbons.
U.S. Pat. No. 3,980,715 is directed to particular nonionic fluorochemical surfactants, particularly those resulting as a reaction of 6-hydroxyhexyl perfluoroisopropyl ether with ethylene oxide or of hexafluorobutenol with propylene oxide and ethylene oxide.
The prior art teaches away from the use of propylene oxide polymers as lubricants, for the reason that their low viscosity indices make such polymers unsuitable for use as lubricants. This is stated in U.S. Pat. No. 2,510,540.
It is desirable to provide a substantially particulate-free homogeneous lubricant additive, which provides effective lubrication in the absence of solid particulates in the composition.